SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93981a9b150897678246b41156b9e8e48fbf3d4eac8e1a703033d8441b2f1019' 
  AND token = '3hL3bWRRG80cShpnQj51bhsFAPImkNV38c67oO7a99c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}